The commissioners thus appointed shall examine the application and make an inspection of all the lands embraced in the proposed district and shall determine what improvements in the way of levees, ditches, drains, settling basins, or change of natural watercourse are necessary for the drainage of the lands described in the petition. Such commissioners, including the engineer, shall file a detailed report of their examination and their findings and file a duplicate thereof in the office of the auditor of each of said counties.
Iowa Code § 468.272
89 Acts, ch 126, §2